China's Foreign Ministry spokesman Liu Weimin, asked if the candidate should come from a developing nation, said the selection should be "based on the merit principle and open competition.''

Close Ranks

The campaign for the helm of an institution that made $57 billion in loans in the last fiscal year will test the capacity of emerging markets to close ranks behind a candidate eight months after they failed to agree on an International Monetary Fund nominee. The World Bank job has always been held by a U.S. national under an informal agreement that also has a European head the IMF. The nomination is subject to approval by the World Bank's executive board.

"As a marker, the emerging markets will put forward some candidates," said Uri Dadush, director of international economics at the Carnegie Endowment for International Peace in Washington. "But it is probably the most likely outcome that the U.S. candidate will prevail just like the European candidate prevailed at the fund."

Christine Lagarde, then France's finance minister, was picked last year over Mexico's Carstens for the IMF job with support from the U.S. as well as nations including Brazil.

Obama's spokesman, Jay Carney, refused to comment on possible successors to Zoellick, who was nominated for the position by then-President George W. Bush in 2007 for a term that ends June 30.

Salary And Benefits

Zoellick received a net salary of $450,378 in the year through June 30, 2011, plus $284,329 in pension and other benefits contributions, according to the bank's annual report.

"There's been a lot of speculation in the press," Carney told reporters traveling with the president to an event in Wisconsin. "I'm not going to confirm any of it."

While Clinton, 64, told State Department employees at a town hall last month that she is tired after 20 years in public life, many of her associates say she might be willing to take the World Bank presidency. It requires fewer hours and less travel than being secretary of state, the people said.